utils/github: add test for fetch_artifact
utils/github: add test for fetch_artifact

sjackman/homebrew,JCount/brew,nandub/brew,vitorgalvao/brew,claui/brew,claui/brew,konqui/brew,mahori/brew,MikeMcQuaid/brew,Homebrew/brew,EricFromCanada/brew,konqui/brew,vitorgalvao/brew,nandub/brew,claui/brew,JCount/brew,reitermarkus/brew,konqui/brew,EricFromCanada/brew,vitorgalvao/brew,mahori/brew,EricFromCanada/brew,reitermarkus/brew,sjackman/homebrew,EricFromCanada/brew,JCount/brew,Homebrew/brew,konqui/brew,mahori/brew,sjackman/homebrew,vitorgalvao/brew,JCount/brew,mahori/brew,Homebrew/brew,reitermarkus/brew,MikeMcQuaid/brew,Homebrew/brew,sjackman/homebrew,nandub/brew,reitermarkus/brew,MikeMcQuaid/brew,claui/brew,MikeMcQuaid/brew,nandub/brew